Just to clarify your misunderstandings... Your actual users are stored in /etc/passwd in unix-like systems. So you can use:

less /etc/passwd

to view the list of users present on your system.

What you have listed from "ls" output there is just a directory listing with permissions, sizes, owners, etc.

The third column says who the owner of the object is, fourth - the group which can use the object under group permissions. The last column names the folder or file in your directory not access permissions like "Shared". The actual permissions are listed in the first column, ex:

drwxrwxrwt

d - means it's a directory

first rwx - owner (third column) is allowed to write, read, execute

second rwx - group (mentioned in the fourth column) is allowed to write, read, execute

last rwt - any other user is allowed to write, read, execute.
t - means sticky bit is set, which means even though the permissions to write are given, only the owner can delete files.

In addition to the information from Alexander and slkck's answers, OS X doesn't use /etc/password for normal user accounts. It uses a directory service to store them in. One way to list the local user accounts I found in an answer on the apple stackexchage under "how-can-i-list-all-user-accounts-in-the-terminal" was: